Guide rails for linear bearings have long been known in the art. Such known guide rails typically have a base body formed from a plastic molding in which there is at least one rail element. The rail element consists of steel and has a ground, drawn or rolled guideway for the rolling bodies of the linear bearing.
The hybrid combination of the plastic body on one side and the rail element on the other side yields a relatively light component which is made rather strong at the point at which it must have great hardness, specifically in the area of the guideway for the rolling bodies. In order to build a light and economical linear guide, therefore, a steel rail is inserted in the plastic base body to increase the bearing number.
In the production of typical guide rails, the steel rail element is inserted into an injection molding tool and then extrusion-coated with plastic material so that only the side of the rail element which has the guideway of the rolling bodies remains free of plastic. Thus, relatively high precision can be achieved insofar as the spacing of two rail elements of a guide rail which are extrusion-coated at the same time with plastic.
In known guide rails such as those described above, it has proven disadvantageous that they do not have the required strength in operation. The inserted steel rail which acts as a rail element with the guide track for the rolling bodies does have sufficient strength. However, especially when the linear bearing is used at elevated temperatures, flow phenomena in the plastic occurs and this can greatly reduce the overall stiffness of the guide rail.